Quintana 1995.

Study characteristics
Methods	Cross‐over trial of methylphenidate versus placebo
Participants	Inclusion criteria: participants recruited from the New York State Psychiatric Institute outpatient clinic DSM‐III‐R criteria for autistic criteria for ASD children off neuroleptics for a period of at least 1 month or if their parents would agree to have them off neuroleptics for 1 month prior to the start of the study. Exclusion criteria: on methylphenidate at any time before entry into the study history of seizure disorder or other major neurological or medical illness Location/setting: USA Sample size: 10 Number of withdrawals/dropouts: none reported Gender: 6 boys, 4 girls Mean age: 8.5 years IQ: mean Developmental Quotient was 64.3 Baseline ABC‐I or other BoC: ABC‐I 11.8 Concomitant medications: participants were required to have been off neuroleptics for a period of at least 1 month prior to the study. History of previous medications: all the children had been on neuroleptic medications (haloperidole etc) at some point in their lives but had not been previously treated with methylphenidate
Interventions	Intervention (methylphenidate) for 2 weeks: started at 10 mg/kg twice a day for the 1st week, then 20 mg/kg twice a day in the 2nd week Placebo for 2 weeks: equivalent placebo
Outcomes	Primary outcomes: irritability, measured using the ABC‐I subscale (Aman 1985) AEs Secondary outcomes: none reported Timing of outcome assessments: unclear
Notes	Study start date: not reported Study end date: not reported Source of funding: not reported Conflicts of interest: none declared
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Details not provided
Allocation concealment (selection bias)	Unclear risk	Details not provided
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	No other comments apart from, "These investigators, the children, and the parents were blind to drug and drug dose."
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	No details
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	10 total participants mentioned, without detail as to dosage allocation, completion of study and individual outcome measures LTFU was not mentioned
Selective reporting (reporting bias)	Low risk	All outcomes measured were reported at baseline and endpoint. Published baseline and endpoint data on all outcome measures
Other bias	Unclear risk	No mention of funding sources or conflicts of interest